In a magnetic disk device, eccentricity may exist between circular tracks written on a magnetic disk of the magnetic disk device and a circular orbit of a magnetic head of the magnetic disk device. In such cases, eccentricity correction may be performed but this causes the seek time of the magnetic head to increase and the performance of the magnetic disk device to decrease. Instead of eccentricity correction, virtual circle control may be performed to control the magnetic head orbit so that it tracks a circle drawn about the spindle center of the magnetic disk. With virtual circle control, the servo sector region of different tracks is set to follow the virtual circular orbit, and the write-and-read of data is performed at each servo sector region.